Pad dyeing of cellulose derivative



Patented June 20, 1950 rim DYEiNG F CELLULOSE' DERIVATIVE FABRICSMADE FROM SIZED SPUN STAPLE- FIBERS FOLLOWED BY DESIZING Wilfred T. Normand, Cumberland, assign or to Celanese Corporation of America, a corporation of Delaware No Drawing. Application September 26, 1947, i

' Serial No. 776,419

This invention relates to the dyeing of fabric materials and relates more particularly to the dyeing of fabric materials made of or containing spun yarns of staple fibers having a basis of cellulose acetate or other organic derivative of cellulose material. I

An object of this invention is the provision of an improved process for the dyeing of fabric materials made of or containing spun yarns of staple fibers having a basis of cellulose acetate or other organic derivative of cellulose material whereby said fabrics may be dyed in even, level shades free of overdyed surface fibers.

Other objects of this invention will appear from the following detailed description.

In weaving fabrics, both the warp and filling yarns are usually sized with a suitable sizing composition prior to the weaving operation in order to impart a measure of physical protection to the yarns. The size placed on the yarns renders them smooth and, therefore, highly resistant to the abrasive action of the moving shuttle supplying the filling yarn and to the mutually abrasive action of the yarns. When dyeing a woven fabric containing the weaving size, the fabric is first scoured to remove the size and then dyed employing a suitable dyebath and dyeing procedure to obtain the desired shade. The sequence of steps comprising scouring and dyeing is satisfactory for many types of fabrics woven of or containing yarns having a basis of cellulose acetate or other'organic derivative of cellulose. However, it has been observed that when fabrics woven of or containing spun yarns of staple fibers having a basis of cellulose acetate or other organic derivative of cellulose material 7 Claims.

sized fabric the fact that such even, level dyeings are obtained, despite the presence of the size, is quite unexpected. After dyeing is completed, the dyed fabric may be de-sized in a suitable scouring bath. The size employed may comprise a casein or gelatin base. size, for example.

The lower aliphatic alcohols which are suitable for use in forming the solvent dyebaths'which we employ for the pad-dyeing operation are those alcohols which are solvents for the dyestuffs employed and which exert at least a swelling or softening action on the organic derivative of cellulose materials. 'While we prefer to employ ethyl alcohol in forming the dyebath, other a1cohols such as methyl alcohol, propyl alcohol, isopropyl alcohol, n-butyl alcohol, secondary butyl alcohol, tertiary butyl alcohol, n-amyl alcohol, secondary amyl alcohol and tertiary amyl alcohol, or mixture of these alcohols may be used. The amount of the alcohol used in the dye liquor will vary depending upon the alcohol or alcohols used.

Optimum results are obtained when the lower are first scoured and dyeing then effected by a mechanical impregnation method such as padding, the staple fiber ends which project from the surface of the fabrics are dyed a considerably deeper shade than the'main body of the 'fabric. This results in a dyed fabric presenting an unevenly dyed appearance.

I have now found that fabrics madeof or con taining spun yarns of staple fibers of cellulose acetate or other organic derivative of cellulose material may be dyed rapidlyin even, level shades bymechanical impregnation methods, such as pad-dyeing, and without anyoverdjr'eingbf the surface fibers if said fabrics are dyed in theraw state, without priorscouring, and while still containingthe size originally placed thereon to aid the weaving operation. The most advantageous results are obtained, in accordancewith my novel process, if the dyebathemployedfor dyeing said raw,- sized fabrics by mech'anical impregnation methods comprises an aqueous alcohol solution of achieved employing sodium thiocyanate.

aliphatic alcohol employed is ethyl alcohol and the latter comprises at least 60% by weight of the dyebath.

As examples of swelling agents for the organic derivative of cellulose materials, there may be mentioned the salts of thiocyanic acid such as ammonium thiocyanate, sodium thiocyanate and potassium thiocyanate, as well as other salts such as zincthiocyanate. Optimum results are The swelling agent is preferably present in amounts of from 1 to, 3% on the weight of the dyebath.

Various 'dyestufl fs for the cellulose acetate or organic derivative of cellulose materials may be employed in accordance with my novel process.

The dyestuffs employed are preferably those dyes which are relatively insoluble in water and which are usually appliedto organic acid ester of cellulose materials in the form of aqueous dispersions.

= f Mixtures of dyestuffs may also be employed.

Theamount of dyestuff dissolved in the dyebath will, of course, vary with the final shade desired in the material which is being dyed and may be from as low a's0.01% up to 5.0% based on the weight of the material to be dyed. Thus, as

a continuous process, the raw, sized fabric may be unwound from a roll, passed through a solution of the dyestuff, then between nipping rolls of a padding mangle which are adjusted to permit the desired amount of dye liquor to be retained in the fabric, and the fabric then subjected directly to washing or scouring whereby the size and any excess dyestuff removed. The duration of the immersion of the fabric in the dye liquor is relatively short and may be from 1 to 6 seconds. If desired, the fabric may be processed through the padding mangle at speeds ranging up to 60 yards per minute.

The staple fibers comprising the spun yarns in the fabrics dyed in accordance with my novel process may have a basis of cellulose acetate or other organic derivative of cellulose. Examples of other organic derivatives of cellulose are cellulose esters such as cellulose propionate, cellulose butyrate, cellulose acetate-propionate and cellulose acetatebutyrate, as well as cellulose ethers such as ethyl cellulose and benzyl cellulose.

In order further to illustrate my' invention, but without being limited thereto, the following examples are given:

Example I A warp of 150 denier, 40 filament cellulose acetate yarn and a 150 denier filling yarn spun of cellulose acetate staple fiber is sized with a size of the following composition applied on a slasher at 140F.

Parts by weight Casein H 50 Triethanolamine 10 Triethyl phosphate 3 Water 1,000

The sized yarns are then woven in the usual manner into a heavy suiting fabric,

The woven fabric containing the weaving size is then padded through a dye solution of the following composition employing a suitable padding mangle:

' 1 Parts by weight Ethyl alcohol (95%) 60 Water 38 Sodium thiocyanate 2 l :4-dimethylamino-anthraquinone 1.5

Cellulose acetate yarns of the deniers and construction described in Example I are sized on a slasher at 150 F. with a size of the following composition.

Parts by weight Gelatin 50 Sulfated fatty oil 3.9 Fatty oil 3.9 Soap 1.7 Water 1,000

Salt v 0.1 Diethylene glycol mono-ethyl ether 5 Sodium ortho-phenyl phenate i.-s 0.5

The sized yarns are then woven into a heavy suiting fabric.

The woven fabric containing the weaving size is then padded through a dye solution of the following composition employing a suitable padding mangle:

Parts by weight Ethyl alcohol 60 Water 38 Sodium thiocyanate 2 1-hydroxy-4-amino-anthraquinone 1.5

The dyed fabric containing the weaving size is then set to a jig for two ends and scoured as described in Example I to remove the size. The scoured fabric is dried and is found to be dyed in a level, even red shade free of overdyed surface fibers.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations ma be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. Process for the coloration of fabrics containing spun yarns of organic derivative of eellulose staple fibers, having thereon a proteinaceous size, in level, even shades free of overdyed surface fibers, which comprises padding said fabrics of said sized spun yarns with a solution of a dyestufi for the organic derivative of cellulose material in an aqueous medium comprising a lower aliphatic alcohol and an inorganic swelling agent for the organic derivative of cellulose material and then souring said dyed fabric to remove the size therefrom.

2. Process for the coloration of fabrics containing spun yarns of cellulose acetate staple fibers, having thereon a proteinaceous size, in level, even shades free of overdyed surface fibers, which comprises padding said fabrics of said sized spun yarns with a solution of a dyestufi for the cellulose acetate material in an aqueous medium comprising a lower aliphatic alcohol and an inorganic swelling agent for the cellulose acetate material and then scouring said dyed fabric to remove the size therefrom.

3. Process for the coloration of fabrics containing spun yarns of organic derivative of cellulose staple fibers, having thereon a proteinaceous size, in level, even shades free of overdyed surface fibers, which comprises padding said fabrics of said sized spun yarns with a solution of a dyestuif for the organic derivative of cellulose material in an aqueous medium comprising a lower aliphatic alcohol and a salt of thiocyanic acid which is a swelling agent for the organic derivative of cellulose material and then scouring said dyed fabric to remove the size therefrom. l

4. Process for the coloration of fabrics containing spun yarns of cellulose acetate staple fibers, having thereon a proteinaceous size, in

' level, even shades free of overdyed surface fibers,

which comprises padding said fabrics of said sized spun yarns with a solution of a dyestuff for the cellulose acetate material in an aqueous medium comprising a lower aliphatic alcohol and a salt of thiocyanic acid which is a swelling agent for the cellulose acetate material and then scouring said dyed fabric to remove the size therefrom.

5. Process for the coloration of fabrics containing spun yarns of cellulose acetate staple fibers, having thereon a proteinaceous size, in level, even shades free, from overdyed surface fibers, which comprises padding said fabrics of said sized spun yarns with a solution of a dyestufi-for the cellulose acetate material in an aquedus medium comprising at least 60% by weight of ethyl alcohol-{and from 1 to 3% by weight of sodium thiocyanate and then scouring said'fd'yed fabric to remove the size therefrom.

,fiiProcess for the coloration of fabrics containing spun yarns of cellulose acetate staple fibers, having thereon a .proteinaceous size, in level; even shades free of overdyed surface fibers, which comprises padding said fabrics of said-sized spun yarns with a solution of 1:4-dimethylamino-anthraquinone in an aqueous medium comprising at least 60% by weight of ethyl alcohol and from 1 to 3% by weight of sodium thiocyanate and then scouring said dyed fabric to remove the size therefrom.

v 7., Process for the coloration of fabrics containing spun yarns of cellulose acetate staple fibers, having thereon a. proteinaceous size, in level, even shades free of overdyed surface fibers, which comprises padding said fabrics of REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 1,883,346 Dreyfus Oct. 18, 1932 2,003,409 Whitehead June 4, 1935 2,274,751 Sowter Mar. 3, 1942 2,428,835 Croft Oct. 14, 1947 OTHER REFERENCES Amer. Dye. Rep. for November 15, 1937, page 711. 

1. PROCESS FOR THE COLORATION OF FABRICS CONTAINING SPUN YARNS OF ORGANIC DERIVATIVE OF CELLULOSE STAPLE FIBERS, HAVING THEREON A PROTEINANCEOUS SIZE, IN LEVEL, EVEN SHADES FREE OF OVERDYED SURFACE FIBERS, WHICH COMPRISES PADDING SAID FABRICS OF SAID SIZED SPUN YARNS WITH A SOLUTION OF A DYESTUFF FOR THE ORGANIC DERIVATIVE OF CELLULOSE MATERIAL IN AN AQUEOUS MEDIUM COMPRISING A LOWER ALIPHATIC ALCOHOL AND AN INORGANIC SWELLING AGENT FOR THE ORGANIC DERIVATIVE OF CELLULOSE MATERIAL AND THEN SOURING SAID DYED FABRIC TO REMOVE THE SIZE THEREFROM. 